JP2001063679A - Assisted motor bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize and reduce weight of an electric drive part motor, improve fuel consumption in addition to efficiently insure necessary maximum torque, and facilitate handling by performing field weakening operation of an electric drive part. SOLUTION: In this assisted motor bicycle, an electric drive part 1 in which a torque detector and a brushless motor, reduction gears and a control circuit are integratedly built, is on the center lower part of a bicycle frame 2, and electrically connected to a battery 3 to be a motor drive energy source. The electric drive part 1 is performed field weakening operation is sufficiently assisted in a normal high load, further in the high speed territory, rotating speed of the motor which can not deal with the vehicle speed by ordinary operation is pulled up to the high speed territory by field weakening operation so as to be able to drive. Hereby, the electric drive part 1 can be miniaturized and the weight can be reduced, in addition to insure necessary maximum torque in high efficiency, improve fuel consumption, and handling can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle with auxiliary power which is driven using human power and auxiliary power.

[0002]

2. Description of the Related Art An auxiliary powered bicycle has a range of 0, t1, x1 surrounded by a regulatory limit line in FIG. 4 as a condition that a driver's license and a helmet wearing obligation are not imposed.
5. The motor must be operated in s1. That is, the assist rate by the electric motor is restricted to 50% or less at the maximum, and the assist rate must be reduced at 15 km / h or more and set to 0 at 24 km / h. FIG. 2 shows a specific example of the operation of the electric drive unit.
Depends on the system configuration.

[0003] The pedal load information is sent from the pedal load detector to the motor drive arithmetic unit in the control unit microprocessor as load torque information. At the same time, the information is sent to a vehicle speed calculation estimating unit, and the vehicle speed is calculated and estimated, and sent to the electric drive unit calculating unit. The computing unit computes operating conditions of the electric drive unit from vehicle speed and pedal load torque information, instructs a power circuit (displayed as PWM inverter) for controlling the electric drive unit motor, and operates the motor.

[0004] The motor of the electric drive unit has a sufficient speed-torque characteristic t0 so that the motor can be operated in the regulation range of FIG.
In general, a motor having -s0 is employed and is operated by PWM duty control.

[0005]

The motor characteristics referred to here are the required maximum rotation speed, that is, the maximum rotation speed (s1) that can be operated up to 24 km / h, the body mass, the weight of the user, and the maximum climbing slope. The maximum torque (t
Determined in 1). Specifically, t1, x15, s in FIG.
For a practical region surrounded by 1, 0, the motor rotation speed-torque characteristic at the rated voltage of the motor is a line connecting t0 and s0.

However, the magnitude of the motor torque is
Since it is determined by the magnitude of the pedaling force of the user, a part of the practical range from the leg strength or physical strength of the user, specifically, x
Area surrounded by 11, x15, s1 (user unnecessary area)
Does not drive the motor. Therefore, the motor characteristics are changed to t
Although it is conceivable to set it to 3, s1, this characteristic causes a problem that the efficiency of the motor is reduced.

If the motor characteristics are t2 and s2,
Although the efficiency is improved, the maximum number of revolutions is reduced and high-speed assistance at the time of light load becomes impossible. Bicycles with auxiliary power use rechargeable batteries, specifically so-called alkaline storage batteries such as nickel-cadmium batteries or nickel-metal hydride batteries, but these batteries have a small size, high energy density, Although it is indispensable to increase the running distance with a smaller capacity battery, the efficiency and mass of the motor are important requirements, and from the viewpoint of the necessary motor characteristics and high efficiency, the size of the motor is large and heavy And result in an increase in the mass of the bicycle, making it difficult to handle.

[0008]

The auxiliary powered bicycle according to the present invention is provided with a human-powered drive unit and an electric drive unit, and is capable of operating the human-powered drive unit alone or the human-powered drive unit and the electric drive unit simultaneously. In motorized bicycles, the electric drive unit is weakened by field operation to reduce the size of the electric drive unit motor, ensure high efficiency and the required maximum torque, and provide a fuel-efficient, lightweight, and easy-to-handle bicycle with auxiliary power. It was realized.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The bicycle with auxiliary power of the present invention
A human-powered drive unit and an electric drive unit are provided side-by-side, wherein the electric drive unit is weakened and field-operated in a bicycle with auxiliary power capable of operating the human-powered drive unit alone or the human-powered drive unit and the electric drive unit simultaneously, Provide sufficient assistance under the heavy load of commonly used auxiliary powered bicycles, and in the high-speed range of auxiliary powered bicycles, reduce the number of motor rotations that cannot cope with the vehicle speed in normal driving and raise it to the high rotation range by field driving drive.

The high-speed region is defined as P in normal operation.
Motor specific rotation speed that maximizes the WM duty-
It refers to a region higher than the operation based on torque characteristics (so-called rated operation).

Further, in the present invention, in at least a part of the high-speed region, the electric drive unit performs the field driving with weakening, the bicycle is assisted even in the high-speed region, and the electric motor is driven by the characteristic rotation speed-torque characteristic of the motor in the low-torque region. Since the driving unit is driven, an efficient electric bicycle with low power consumption is obtained.

In addition, when the operation is performed by increasing or decreasing the assist ratio of the electric drive unit with respect to the increase or decrease of the load of the manual drive unit, the assist ratio / pedal load is larger when the pedal load is larger than when the pedal load is smaller. When the value is large, appropriate assistance can be performed in accordance with the area where the load requiring assistance is large, or the magnitude of the fluctuation of the load, and an energy saving effect can be expected.

[0013]

FIG. 1 shows a first embodiment of a bicycle with auxiliary power according to the present invention. A driving unit 1 in which a torque detector, a brushless motor, a speed reducer, and a control circuit are integrally incorporated is provided at a lower center portion of the bicycle frame 2 and is electrically connected to a battery 3 serving as a motor driving energy source.

The drive section is attached to the bicycle frame with a plurality of screws. The electric drive is operated by the system shown in FIG. In the manual drive unit, the pedal load is detected, this load information is input to a motor drive calculation unit of a control unit microprocessor (indicated as MPU), and this information is sent to a vehicle speed calculation and estimation unit to calculate the vehicle speed. The estimated value is input to the motor drive calculation unit.

The motor drive calculation section calculates motor drive conditions from information on pedal load and vehicle speed, and inputs the motor drive conditions to the motor drive circuit. The motor drive circuit drives the motor under predetermined conditions.
Here, a method is used in which the vehicle speed is inferred from the periodic change of the pedal load. Alternatively, a vehicle speed detection unit may be provided separately and the information may be input to the motor drive calculation unit.

FIG. 3 shows a specific operation example. The output of the electric drive unit is 50% of the bicycle output, and decreases at a vehicle speed of 15 km / h or more, and becomes 0 at 24 km / h.
It operates in the area surrounded by 01 and s11.

In such an auxiliary area, there is a part (user unnecessary area) which is not actually used by the user due to leg strength or physical strength, and a normal motor rotation speed-torque is set so as not to include this unused part. Characteristic is t0-s1
Let it be 2. However, if the intrinsic rotational speed-torque characteristic of the motor is t0-s12, the maximum speed of the motor becomes t12, and the motor torque becomes 0 at a vehicle speed of about 20 km / h. Increase speed to s11.

As described above, the rotational speed-torque characteristic of the normal operation is reduced from the rotational speed-torque characteristic of the auxiliary region, and in the high torque portion, the maximum rotational speed of the motor is increased to the auxiliary region by the field weakening operation. It became possible to drive in rotation.

That is, although the motor torque increases with the magnitude of the pedal load, the motor operates at a pedal load within the range of the torque t11, and the rotational speed specific to the motor-
When the motor rotation speed becomes higher than the intersection x11 with the torque characteristic line, the motor is operated according to the rotation speed-torque characteristic inherent to the motor. Further, when the vehicle is driven at a speed exceeding the predetermined speed y11, the vehicle is driven with a weak field and the vehicle speed becomes 24 km / h.
At 11, the motor output torque becomes zero. When the field-weakening operation is not performed, the motor torque becomes 0 at a speed s12 lower than 24 km / h, and the auxiliary power does not function in a practical range.
1, an area surrounded by s11 occurs, and the convenience as a bicycle is reduced, but it is possible to assist up to 24 km / h by a weak field.

When the pedal load is light, the motor must be operated in a range surrounded by t02, x02, and s11 in FIG. 3, which is normally regarded as a bicycle. In this case, the motor is operated at the torque t12, and when the speed exceeds a predetermined speed y12, the field weakening operation is performed, and the auxiliary is set to 0 at s11.
The selection of the auxiliary rate for the pedal load is to always operate the motor at a constant rate within the regulation value, and in the field weakening operation or the rated operation as described above in the high-speed region, the auxiliary rate is consequently determined according to the speed-torque characteristic inherent to the motor. Or a method of selecting an assisting ratio within a regulation value according to the magnitude of the pedal load, operating the motor, and assisting in the field weakening operation or the rated operation in the high-speed region as described above.

As an example of the selection of the auxiliary rate, there is a method shown in FIG. That is, when the load is light, the auxiliary rate is set to be low, and the increase rate of the auxiliary rate is set to be larger than the increase rate of the load. According to this method, appropriate assistance can be performed according to the area where the load requiring assistance is large or the magnitude of the fluctuation of the load, and an energy saving effect can be expected.

[0022]

The present invention reduces the size of the electric drive unit motor by weakening the electric drive unit in the high-speed region and performing the field operation.
After securing the required maximum torque with high efficiency, fuel efficiency is good,
A lightweight, easy-to-handle bicycle with auxiliary power has been realized.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of a bicycle with auxiliary power according to the present invention.

FIG. 2 is a system configuration diagram of the present invention.

FIG. 3 is a diagram showing a motor operation example of the present invention.

FIG. 4 is a diagram showing a conventional motor characteristic and an operation example.

FIG. 5 is a diagram showing an example of an auxiliary ratio selection according to the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive part 2 Bicycle frame 3 Battery

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryo Matsuo 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3D035 AA01

Claims (5)

[Claims] In a bicycle with an auxiliary power, wherein a human-powered drive unit and an electric-powered drive unit are provided side by side, and the human-powered drive unit or the human-powered drive unit and the electric-powered drive unit can be operated at the same time, the electric-powered drive unit is weakened in field operation. An auxiliary powered bicycle that is capable of doing. 2. The bicycle with auxiliary power according to claim 1, wherein the maximum rotation speed of the motor is increased by the field weakening operation as compared with the normal operation. 3. A motor rotation speed-torque characteristic when the electric drive unit is weakened and a field operation is performed, and a motor rotation speed in a normal operation.
The bicycle with an auxiliary power according to claim 1, wherein the torque characteristic does not include a user unnecessary area of the bicycle with an auxiliary power. 4. The bicycle with auxiliary power according to claim 1, wherein the bicycle is operated by increasing or decreasing the assist ratio of the electric drive unit with respect to increase or decrease in the load of the manual drive unit. 5. The bicycle with auxiliary power according to claim 4, wherein the value of the auxiliary ratio / pedal load becomes larger when the pedal load is larger than when the pedal load is smaller.